1. Field of the Invention
The present invention relates to a horizontal linear vibrator and, more particularly, to a horizontal linear vibrator designed to be mounted on a personal mobile terminal to vibrate.
2. Description of the Related Art
In general, one of the key functions requisite for communication devices is a call reception function. Commonly used call reception functions include a sound generating function that generates a melody or a bell sound and a vibration function that transfers vibrations to a device.
Among the functions, the vibration function is commonly used so as not to interfere with others by preventing a melody or a bell sound from being transferred to the exterior through a speaker.
In order to implement such a vibration function, in general, a small vibration motor is driven to transfer driving force to a case of a device to make the device vibrate.
In particular, recently, as mobile terminals have been reduced in size and have improved in quality, the use of a touch screen type display device has been greatly favored, requiring a vibration generation function when a touch is applied to the touch screen, so the improvement of the vibration motor has gradually taken place.
A vibration motor applied to existing mobile phones generates rotatory power in order to rotate a rotational part of an unbalance mass, thus obtaining mechanical vibrations, and in this case, rotatory power is generated such that it is mostly subjected to a rectifying action through a brush and a contact point of a commutator (or rectifier) to provide current to a rotor coil.
However, in the brush type structure using a commutator, when the motor rotates, the brush passes through the gap between segments of the commutator, resulting in mechanical friction and an electrical spark as well as abrading the brush and the commutator and thereby shortening the life span of the motor.
In addition, because voltage is applied to the motor by using a moment of inertia, time is taken to reach a target amount of vibrations, so it is difficult to implement vibrations suitable for touch screen-employed personal mobile terminals and the like.
In order to overcome such disadvantages in terms of life span and responsiveness, a linear vibrator with the exclusion of a rotational principle is being used.
A linear vibrator generates vibrations by electromagnetic force having a resonance frequency determined by using a spring installed therein and a mass body coupled with the spring.
However, such a linear vibrator is designed to vibrate in a vertical direction and is able to generate vibrations only when the linear vibrator moves by securing the upper and lower displacements of the mass body provided therein. This puts limitations on the thickness thereof.
Also, in order to realize a large amount of vibrations, the thickness thereof should be increased. For this reason, it is required to have a larger space for mounting the vibrator on a personal mobile terminal, thereby being unsuitable for miniaturization.